title: Dissecting the EGFR-PI3K-AKT pathway in oral cancer highlights the role of the EGFR variant III and its clinical relevance.
abstract: BACKGROUND
  Dysregulated epidermal growth factor receptor (EGFR)-phosphoinositide-3-kinase (PI3K)-AKT signaling is considered pivotal for oral cancer, and the pathway is a potential candidate for therapeutic targeting.
  
  
  RESULTS
  A total of 108 archival samples which were from surgically resected oral cancer were examined. Immunohistochemical staining showed the protein expression of membranous wild-type EGFR and cytoplasmic phosphorylated AKT was detected in 63.9% and 86.9% of the specimens, respectively. In 49.1% of the samples, no phosphatase and tensin homolog (PTEN) expression was detected. With regard to the EGFR variant III (EGFRvIII), 75.0% of the samples showed positive expression for moderate to severe staining, 31.5% of which had high expression levels. Real-time polymerase chain reaction assays for gene copy number assessment of PIK3CA revealed that 24.8% of the samples had alterations, and of EGFR showed that 49.0% had amplification. Direct sequencing of PIK3CA gene showed 2.3% of the samples had a hotspot point mutation. Statistical assessment showed the expression of the EGFRvIII correlated with the T classification and TNM stage. The Kaplan-Meier analyses for patient survival showed that the individual status of phosphorylated AKT and EGFRvIII led to significant differences in survival outcome. The multivariate analysis indicated that phosphorylated AKT, EGFRvIII expression and disease stage were patient survival determinants.
  
  
  CONCLUSIONS
  Aberrations in the EGFR-PI3K-AKT pathway were frequently found in oral cancers. EGFRvIII and phosphorylated AKT were predictors for the patient survival and clinical outcome.
authors.affiliation: Institute of Clinical Medicine College of Medicine, National Cheng Kung University, 7th Floor, No.35 Xiaodong Rd., Tainan City 701, Taiwan.
authors.forename: Kwang-Yu
authors.initials: KY
authors.lastname: Chang
authors.forename: Shan-Yin
authors.initials: SY
authors.lastname: Tsai
authors.forename: Shang-Hung
authors.initials: SH
authors.lastname: Chen
authors.forename: Hsiao-Hui
authors.initials: HH
authors.lastname: Tsou
authors.forename: Chia-Jui
authors.initials: CJ
authors.lastname: Yen
authors.forename: Ko-Jiunn
authors.initials: KJ
authors.lastname: Liu
authors.forename: Hsun-Lang
authors.initials: HL
authors.lastname: Fang
authors.forename: Hung-Chang
authors.initials: HC
authors.lastname: Wu
authors.forename: Bin-Fay
authors.initials: BF
authors.lastname: Chuang
authors.forename: Shao-Wen
authors.initials: SW
authors.lastname: Chou
authors.forename: Careen K
authors.initials: CK
authors.lastname: Tang
authors.forename: Shyun-Yeu
authors.initials: SY
authors.lastname: Liu
authors.forename: Pei-Jung
authors.initials: PJ
authors.lastname: Lu
authors.forename: Ching-Yu
authors.initials: CY
authors.lastname: Yen
authors.forename: Jang-Yang
authors.initials: JY
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: C410723:epidermal growth factor receptor VIII; D019869:Phosphatidylinositol 3-Kinases; D066246:ErbB Receptors; D051057:Proto-Oncogene Proteins c-akt